RESUMO
The escalating obesity epidemic and aging population have propelled metabolic dysfunction-associated steatohepatitis (MASH) to the forefront of public health concerns. The activation of FXR shows promise to combat MASH and its detrimental consequences. However, the specific alterations within the MASH-related transcriptional network remain elusive, hindering the development of more precise and effective therapeutic strategies. Through a comprehensive analysis of liver RNA-seq data from human and mouse MASH samples, we identified central perturbations within the MASH-associated transcriptional network, including disrupted cellular metabolism and mitochondrial function, decreased tissue repair capability, and increased inflammation and fibrosis. By employing integrated transcriptome profiling of diverse FXR agonists-treated mice, FXR liver-specific knockout mice, and open-source human datasets, we determined that hepatic FXR activation effectively ameliorated MASH by reversing the dysregulated metabolic and inflammatory networks implicated in MASH pathogenesis. This mitigation encompassed resolving fibrosis and reducing immune infiltration. By understanding the core regulatory network of FXR, which is directly correlated with disease severity and treatment response, we identified approximately one-third of the patients who could potentially benefit from FXR agonist therapy. A similar analysis involving intestinal RNA-seq data from FXR agonists-treated mice and FXR intestine-specific knockout mice revealed that intestinal FXR activation attenuates intestinal inflammation, and has promise in attenuating hepatic inflammation and fibrosis. Collectively, our study uncovers the intricate pathophysiological features of MASH at a transcriptional level and highlights the complex interplay between FXR activation and both MASH progression and regression. These findings contribute to precise drug development, utilization, and efficacy evaluation, ultimately aiming to improve patient outcomes.
RESUMO
Previous studies demonstrated that prolonged exposure to elevated levels of free fatty acids (FFA), especially saturated fatty acids, could lead to pancreatic ß-cell apoptosis, which plays an important role in the progression of type 2 diabetes (T2D). Diacylglycerol acyltransferase 1 (DGAT1), an enzyme that catalyzes the final step of triglyceride (TG) synthesis, has been reported as a novel target for the treatment of multiple metabolic diseases. In this study we evaluated the potential beneficial effects of DGAT1 inhibitors on pancreatic ß-cells, and further verified their antidiabetic effects in db/db mice. We showed that DGAT1 inhibitors (4a and LCQ908) at the concentration of 1 µM significantly ameliorated palmitic acid (PA)-induced apoptosis in MIN6 pancreatic ß-cells and primary cultured mouse islets; oral administration of a DGAT1 inhibitor (4a) (100 mg/kg) for 4 weeks significantly reduced the apoptosis of pancreatic islets in db/db mice. Meanwhile, 4a administration significantly decreased fasting blood glucose and TG levels, and improved glucose tolerance and insulin tolerance in db/db mice. Furthermore, we revealed that pretreatment with 4a (1 µM) significantly alleviated PA-induced intracellular lipid accumulation, endoplasmic reticulum (ER) stress, and proinflammatory responses in MIN6 cells, which might contribute to the protective effects of DGAT1 inhibitors on pancreatic ß-cells. These findings provided a better understanding of the antidiabetic effects of DGAT1 inhibitors.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Hipoglicemiantes/farmacologia , Animais , Apoptose/efeitos dos fármacos , Glicemia/efeitos dos fármacos , Linhagem Celular , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Insulina/metabolismo , Células Secretoras de Insulina/efeitos dos fármacos , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ácido Palmítico/toxicidadeRESUMO
Gluconeogenesis is a major source of hyperglycemia in patients with type 2 diabetes mellitus (T2DM), thus targeting gluconeogenesis to suppress glucose production is a promising strategy for anti-T2DM drug discovery. In our preliminary in vitro studies, we found that a small-molecule (E)-3-(2-(quinoline-4-yl)vinyl)-1H-indol-6-ol (QVO) inhibited the hepatic glucose production (HGP) in primary hepatocytes. We further revealed that QVO suppressed hepatic gluconeogenesis involving calmodulin-dependent protein kinase kinase ß- and liver kinase B1-adenosine monophosphate-activated protein kinase (AMPK) pathways as well as AMPK-independent mitochondrial function-related signaling pathway. To evaluate QVO's anti-T2DM activity in vivo, which was impeded by the complicated synthesis route of QVO with a low yield, we designed and synthesized 4-[2-(1H-indol-3-yl)vinyl]quinoline (IVQ) as a prodrug with easier synthesis route and higher yield. IVQ did not inhibit the HGP in primary hepatocytes in vitro. Pharmacokinetic studies demonstrated that IVQ was quickly converted to QVO in mice and rats following administration. In both db/db and ob/ob mice, oral administration of IVQ hydrochloride (IVQ-HCl) (23 and 46 mg/kg every day, for 5 weeks) ameliorated hyperglycemia, and suppressed hepatic gluconeogenesis and activated AMPK signaling pathway in the liver tissues. Furthermore, IVQ caused neither cardiovascular system dysfunction nor genotoxicity. The good druggability of IVQ has highlighted its potential in the treatment of T2DM and the prodrug design for anti-T2DM drug development.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Gluconeogênese/efeitos dos fármacos , Hipoglicemiantes/uso terapêutico , Indóis/uso terapêutico , Pró-Fármacos/uso terapêutico , Quinolinas/uso terapêutico , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Ativadores de Enzimas/uso terapêutico , Ativadores de Enzimas/toxicidade , Inibidores Enzimáticos/uso terapêutico , Inibidores Enzimáticos/toxicidade , Glucose-6-Fosfatase/antagonistas & inibidores , Hepatócitos/efeitos dos fármacos , Hipoglicemiantes/toxicidade , Indóis/toxicidade , Fígado/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Fosfoenolpiruvato Carboxiquinase (GTP)/antagonistas & inibidores , Pró-Fármacos/toxicidade , Quinolinas/toxicidade , Transdução de Sinais/efeitos dos fármacosRESUMO
(2'R)-2',3'-Dihydro-2'-(1-hydroxy-1-methylethyl)-2,6'-bibenzofuran-6,4'-diol (DHMB) is a natural compound extracted from Morus notabilis. It was found that DHMB acts as a competitive inhibitor against mushroom tyrosinase with a Ki value of 14.77 µM. Docking results further indicated that it could form strong interactions with one copper ion with a distance of 2.7 Å, suggesting the mechanism of inhibition might be due to chelating copper ions in the active site. Furthermore, melanin production in B16-F10 murine melanoma cells was significantly inhibited by DHMB in a concentration-dependent manner without cytotoxicity. The results of western blotting also showed that DHMB decreased 3-isobuty-1-methxlzanthine-induced mature tyrosinase expression. Taken together, these findings indicated that DHMB may be a new promising pigmentation-altering agent for agriculture, cosmetic, and therapeutic applications.
Assuntos
Agaricales/enzimologia , Benzofuranos/química , Melaninas/biossíntese , Melanoma Experimental/metabolismo , Monofenol Mono-Oxigenase/antagonistas & inibidores , Animais , Linhagem Celular Tumoral , AMP Cíclico/metabolismo , Inibidores Enzimáticos/química , Camundongos , Simulação de Acoplamento Molecular , Morus/químicaRESUMO
Aphadilactones A-D (1-4), four diastereoisomers possessing an unprecedented carbon skeleton, were isolated from the Meliaceae plant Aphanamixis grandifolia. Their challenging structures and absolute configurations were determined by a combination of spectroscopic data, chemical degradation, fragment synthesis, experimental CD spectra, and ECD calculations. Aphadilactone C (3) with the 5S,11S,5'S,11'S configuration showed potent and selective inhibition against the diacylglycerol O-acyltransferase-1 (DGAT-1) enzyme (IC50 = 0.46 ± 0.09 µM, selectivity index > 217) and is the strongest natural DGAT-1 inhibitor discovered to date. In addition, compounds 1-4 showed significant antimalarial activities with IC50 values of 190 ± 60, 1350 ± 150, 170 ± 10, and 120 ± 50 nM, respectively.
Assuntos
Antimaláricos/farmacologia , Diacilglicerol O-Aciltransferase/antagonistas & inibidores , Diterpenos/farmacologia , Inibidores Enzimáticos/farmacologia , Meliaceae/química , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/química , Antimaláricos/isolamento & purificação , Diacilglicerol O-Aciltransferase/metabolismo , Dimerização , Diterpenos/química , Diterpenos/isolamento & purificação , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Humanos , Conformação Molecular , Testes de Sensibilidade Parasitária , Proteínas Recombinantes/metabolismo , Relação Estrutura-AtividadeRESUMO
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with complicated pathogenesis and targeting gluconeogenesis inhibition is a promising strategy for anti-diabetic drug discovery. G protein-coupled receptors (GPCRs) are classified as distinct families by heterotrimeric G proteins, primarily including Gαs, Gαi and Gαq. Gαs-coupled GPCRs function potently in the regulation of hepatic gluconeogenesis by activating cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway and Gαi-coupled GPCRs exhibit inhibitory effect on adenylyl cyclase and reduce intracellular cAMP level. However, little is known about the regulation of Gαq-coupled GPCRs in hepatic gluconeogenesis. Here, small-molecule 2-(2,4-dimethoxy-3-methylphenyl)-7-(thiophen-2-yl)-9-(trifluoromethyl)-2,3-dihydropyrido[3',2':4,5]thieno[3,2-d]pyrimidin-4(1H)-one (DMT) was determined to suppress hepatic glucose production and reduce mRNA levels of gluconeogenic genes. Treatment of DMT in db/db mice decreased fasting blood glucose and hemoglobin A1C (HbA1c) levels, while improved glucose tolerance and pyruvate tolerance. Mechanism study demonstrated that DMT-inhibited gluconeogenesis by regulating the Gαq/phospholipase C (PLC)/inositol-1,4,5-triphosphate receptor (IP3R)-mediated calcium (Ca2+)/calmodulin (CaM)/phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/protein kinase B (AKT)/forkhead box protein O1 (FOXO1) signaling pathway. To our knowledge, DMT might be the first reported small molecule able to suppress hepatic gluconeogenesis by regulating Gαq signaling, and our current work has also highlighted the potential of DMT in the treatment of T2DM.
Assuntos
Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Gluconeogênese/efeitos dos fármacos , Fígado/metabolismo , Transdução de Sinais/efeitos dos fármacos , Tiofenos/farmacologia , Animais , Cálcio/metabolismo , Calmodulina/metabolismo , Proteína Forkhead Box O1/metabolismo , Hiperglicemia/tratamento farmacológico , Hiperglicemia/patologia , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Insulina/farmacologia , Fígado/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Tiofenos/sangue , Tiofenos/química , Tiofenos/farmacocinética , Fosfolipases Tipo C/metabolismoRESUMO
Impaired glucose-stimulated insulin secretion (GSIS) and increasing ß-cell death are two typical dysfunctions of pancreatic ß-cells in individuals that are destined to develop type 2 diabetes, and improvement of ß-cell function through GSIS enhancement and/or inhibition of ß-cell death is a promising strategy for anti-diabetic therapy. In this study, we discovered that the small molecule, N-(2-benzoylphenyl)-5-bromo-2-thiophenecarboxamide (BBT), was effective in both potentiating GSIS and protecting ß-cells from cytokine- or streptozotocin (STZ)-induced cell death. Results of further studies revealed that cAMP/PKA and long-lasting (L-type) voltage-dependent Ca(2) (+) channel/CaMK2 pathways were involved in the action of BBT against GSIS, and that the cAMP/PKA pathway was essential for the protective action of BBT on ß-cells. An assay using the model of type 2 diabetic mice induced by high-fat diet combined with STZ (STZ/HFD) demonstrated that BBT administration efficiently restored ß-cell functions as indicated by the increased plasma insulin level and decrease in the ß-cell loss induced by STZ/HFD. Moreover, the results indicated that BBT treatment decreased fasting blood glucose and HbA1c and improved oral glucose tolerance further highlighting the potential of BBT in anti-hyperglycemia research.